Propeller



C. H. HAVILL PROPELLEH Nov. 5, 1935.

Filed June 25, 1934 2 Sheets-Sheet 1 INVENTOR Nov. 5, 1935. 1 c. H.HAvlLL' PROPELLER Filed June 25, 1954 2 Sheets-Sheet 2 hmm n il .5*

R O T N E v m.

Patented Nov. 5, 1935 PROPELLER.

Clinton H. Havill, East Orange, N. J., assigner to Eclipse AviationCorporation, East Orange, v N. J., a corporation of New JerseyApplication June 25, 1934, Serial No. 732,332

16 Claims.

This invention relates to propellers and more particularly to propellersof the type having a plurality of blades, the angularity or pitch ofwhich may be varied during operation.

One of the objects of the present invention is to provide, in a variablepitch propeller, a novel pitch-limiting mechanism so constituted as tobe adjustable to various positions during operation of the propeller,whereby the pitch limits of the latter may be readily adjusted tocompensate for variable conditions encountered during flight of anaircraft equipped with the invention.

Another object of the invention is to provide, in a construction of theabove character, a novel mechanism permitting a ready variation of thelower pitch limit of the propeller blades to the end that the rate ofrevolutions vof the propeller may be varied to meet different operatingconditions and thus realize a maximum engine and propeller eiciency atall times. y

Still another object is to provide a propeller having a plurality ofblades, the pitch of which is automatically varied during operation inaccordance with the thrust of the blades, in combination with amanually-adjustable mechanism eiective during operation of the propellerto positively limit the pitch attainable by the blades.

A furtherg object is to provide, in a variable pitch propeller of theautomatic type, a novel construction including a manually-adjustablestop mechanism for limiting the pitch of the blades.

A still further object is to provide, in a propeller of the typeembodying a hub movable axially of the drive shaft for changing thepitch of the blades, a novel manually-operable mechanism cooperable witha device carried by the propeller for positively arresting relativemovel ment of the propeller hub with respect lto the propeller shaft inorder to positively limit the reduction in the pitch of the bladesduring operation of the propeller.

A still further object is to provide a novel variable pitch propellerand pitch-limiting mechaever, that the drawings are 'for purposes ofillustration only and are not designed as a definition of the limits ofthe invention, reference. being had for this purpose to the appendedclaims.

In the drawings, 5

Fig. 1 is a. side view, partly in section, of a propeller illustratingone embodiment of the present invention;

Fig. 2 is an enlarged side view, partly in section, of certain oftheparts constituting the pitchl0 limiting mechanism shown in Fig. 1;

Fig. 3 is a side view, partly in section, of a propeller illustrating aslightly different form of the invention, and

Fig. 4 is an enlarged side view, partly in secl5 tion, of certain of theparts constituting the pitch-limiting mechanism shown in Fig. 3.

Referring more particularly to Figs. 1 and 2, a variable pitch propellerembodying the principles of the present invention is illustrated there-2O in as being constituted by a rotatable engine shaft or extensionthereof 5 and a hub B drivably connected thereto in any suitable mannerbut relatively movable longitudinally thereof in response to the thrustexerted by the blades. The 25 hub is provided with a plurality lofradially-extending sockets 'I adapted to rotatably receive the inner orroot ends of propeller blades 8, there being also provided suitable linkmechanisms 9 interconnecting the blades with a plate member 30 I0 xedlysecured to the propeller shaft, these last named mechanisms beingeiective to vary the pitch of the blades 'during the aforesaidthrust-responsive movement of the hub relative to the shaft.

In order to yieldingly oppose forward axial movement4 of the hub withrespect to the shaft with the degree of thrust exerted by the blades 40under the existing conditions of operation, there is preferably provideda plurality of resilient members `,such as for example, coil springs y II, arranged in a. circle concentric with respect to the shaft andinterposed between the hub 6 and Va 45 plate I2 secured in any suitablemanner to a fora Ward extension I3 of driving block I4, this latterelement being suitably splined to the shaft 5 and forming a portion ofthe driving connection between said shaft and the propeller hub. It isto be 50 noted that when the parts are in the position shown in Fig. 1,the pitch of the blades is a maximum, the pitch being gradually reducedduring forward movement of the hub relative to the shaft in response tothe thrust of the blades, the above mentioned resilient members I I,however, serving to yieldably oppose such movement and to arrest the hubin such a position relative to the shaft that the pitch assumed by theblades will be substantially proportionalto the thrust thereof and suchas to yield a substantially maximum propeller eiciency for theconditions of thrust imposed.

One of the features of the present invention resides in the provision ofmeans for predetermining the variation in the pitch of the blades andmore particularly to provide means whereby one of the pitch limits maybe readily varied during operation of the propeller. In the form shown,such means include a plurality of pins or studs I5 secured to thepropeller hub 6 and. carrying a sleeve I6 surrounding the propellershaft and slidable along a member I1 secured to said shaft, during axialmovement of the hub. The inner race of ball bearing I8 is secured to thesleeve I6 by any suitable means including a threaded ring I9, the outerrace of such bearing being freely slidable with respect to amanually-operable member 20. An abutment 2l secured to thecsleeve I1forms a stop mechanism for limiting movement of the sleeve I6 in onedirection with respect to the shaft.

For the purpose of limiting movement of the sleeve I6 in the oppositedirection with respect to the shaft, an exteriorly-threaded nut 22cooperable with a stationary interiorly-threaded sleeve 23 is providedand has formed thereon an abutment flange 24 constituting a stopmechanism for limiting movement of the sleeve I6 to the left as viewedin Fig. 1, through engagement of the outer race of bearing I8 therewith.In this manner, movement of the hub to the left as viewed in Fig. 1, inthe direction to reduce the pitch of the blades, is arrested uponengagement of the flange 24 of the nut 22 with the outer race of thebearing I1 carried by the sleeve I6 movable with the hub during changein pitch.

In order that the position of the abutment 24 may be varied duringoperation of the propeller to the end that the reduction in pitch may bepredetermined to secure maximum eflciency during various conditions ofoperation, manuallyoperable means are provided for rotating the nut 22with respect to the threaded sleeve 23 to move the former with respectto the latter. As shown, such means include the manually-operable member20 which, as shown, is rotatably mounted upon a ring 25 secured to astationary portion 26 of the engine casing, the said member having gearteeth formed on the periphery thereof in constantengagement with gear21, which latter may be controlled in any suitable manner by theoperator. The member 20 is also provided with a plurality of flngers 28extending parallel tothe propeller shaft and adapted to engagecorresponding slots 29 formed in the inner surface of the nut 22, sucharrangement permitting ready rotation of the latter in order to move thesame longitudinally with respect to the stationary nut 23, thuseffecting a variation in the position of the flange 24 with regard tothe bearing I8 and hence effecting an efficient mechanism for limitingthe movement of the hub with respect to the propeller shaft.

Referring more particularly to Figs. 3 and 4, wherein a slightlymodified form of the pitchlimiting mechanism is disclosed, the pins orstuds I5 are secured to a sleeve 40 through a laterallyextending flange4I, the said sleeve being slidable along sleeve 42 during movement ofthe hub with respect to the propeller shaft. In this form of theinvention, the inner race of ball bearing 43 is freely slidable withrespect to sleeve 40. the latter carrying an abutment or suitable stopmechanism, preferably formed as a nut 44 which is engageable with theinner race of the bearing to limit movement of the hub with respect tothe shaft toward the left as viewed in Fig. 3. The outer race of 5bearing 43 is suitably secured to the exteriorlythreaded nut 44 which,as in the rst form of thel invention, cooperates with aninteriorlythreaded sleeve 45 suitably securedas by means of stud 46 to astationary portion 41 of the engine 10 crank case. The nut 44 isprovided with suitable interiorly-disposed slots 48 for reception offingers 49 formed integrally with the manually-adjustable member 50which is suitably rotatably mornted on the crank case member 41 and maybe ro- 15 tated with respect thereto as by means of gear 5I suitablyconnected t'o any operator-controlled means for remote manipulation.

In the operation of this form of the invention, rotation of gear 5I willeffect relative move- 20 ment between nut 44 and threaded sleeve 45through the manually-operable member '50 and and thus position bearing43 in any desired locav tion with respect to the sleeve 40. Movement ofthe hub tothe left as shown in Fig. 3, to effect 25 a reductionv in thepitch of the blades, will be arrested as soon as the nut 44 carried bysleeve 40 engages the adjacent face of the inner race of bearing 43. Inthis manner, thev lower pitch limit of the blades may be readilypredetermined and 30 adjusted during operation of the propeller.

'Ihere is thus provided by the present invention a variable pitchpropeller of the type wherein the pitch of the blades is automaticallyvaried during operation and embodying a construction 35 wherein thepitch is varied between predetermined limits. The provision of themanually-adjustable pitch-limiting stop mechanism enables the lowerpitch limit to be readily varied during operation of the propeller tothe end that the 40 maximum rate of revolutions .of the engine may bepredetermined thus permitting operation of the engine and propeller atmaximum efficiency under all conditions.

While two embodiments of the invention have 45 been shown and describedherein, it is to be understood that the invention is not limited theretobut may be embodied in other forms, as well understood by those skilledin the art. Reference will, therefore, be had to the appended claims for50 a definition of the limits of the invention.

What is claimed is:

l. A variable pitch propeller comprising a rotatable shaft, a hubdrivably connected to and longitudinally movable along said shaft, aplurality of 55 blades rotatably mounted in said hub, connectionsbetween said shaft and blades for` changing the angularity of the bladesin response to movement of the hub longitudinally of the'shaft, stopmeans for limiting such movement of the hub, and manually-operable meansfor adjusting said stop means during operation of the propellerindependently of said movement of the hub. j

2. A variable pitch propeller comprising a rotatable shaft, a hubdrivably connected to and 65 longitudinally movable along said shaft, aplurality of blades rotatably mounted in said hub, connections betweensaid shaft and blades for changing the angularity of the blades inresponse to movement of the hub longitudinally of the shaft, means forpositively limiting movement of the hub along the shaft in onedlrection, and manually-operable control means for adjusting saidhunting means during operation of the propeller independently of saidmovement of the hub. 75

3. Avariable pitch propeller comprising a rotatable shaft, a hubdrivably connected to and longitudinally movable along said shaft apredetermined extent, a plurality of blades rotatably mounted in saidhub, connections between said shaft and blades for changing theangularity of the blades in response to movement of the hublongitudinally of the shaft, and manually-operable means effectiveduring operation of the propeller for varying said predetermined extentindependently of said movement of the hub.

4. In a variable pitch propeller having a hub and a plurality of bladesrotatable about their longitudinal axes for changing the pitch thereof,means including said hub for eifecting pitchchanging rotation of saidblades, means for limiting operation of said pitch-changing means duringa decrease in the pitch of the blades, and manually-operable meansdirectly cooperating with said hunting means for adjusting the latterduring operation of the propeller.

5. In a variable pitch propeller having a hub and a plurality of bladesrotatable about their longitudinal axes for changing the pitch thereof,means including said hub for effecting pitchchanging rotation of saidblades, means including a stop mechanism for positively limitingoperation of said pitch-changing means during a decrease in the pitch ofthe blades, and manuallyadjustable `means directly cooperating with saidstop mechanism for varying the position of the latter during operationofthe propeller in order to change the lower pitch limit of the blades.

6. In a variable pitch propeller of the type hav- 'ing a hub movablealong a propeller shaft in accordance with the thrust of the propellerblades, the combination with said propeller, of means operable to varythe pitch of the propeller blades during such movement of the hub, andmeans manually operable independently of said movement of the hub forpositively variably limiting the movement of said hub along said shaftduring rotation ofthe propeller.

7. In a variable pitch propeller of the type having a hub movable alonga propeller shaft in accordance with theV thrust of the propellerblades, the combination with said propeller, of means operable to varythe pitch of the propeller blades during such movement of the hub, andmeans manually operable during rotation of the propeller for positivelyvariably limiting the movement of said hub along said shaft, said lastnamed means including a pair of relatively-rotatable members.

8. In a vat-iable pitch propeller having a hub and a plurality of bladesrotatable about their longitudinal axes for changing the pitch thereof,means including said hub for effecting pitchchanging rotation of saidblades, means including a pair of relatively-movable members forlimiting operation of said pitch-changing means during a decrease in thepitchof the blades, and manually-operable means directly cooperatingwith one of said members for moving the latter with respect to the otherof said members during operation of the propeller.

9.` In a propeller having a plurality of blades, means actuated by thethrust of the blades for automatically varying the pitch thereof, meansfor .predetermining the extent of operation of said pitch-varying meanswithin predetermined limits, and means manually operable during rotationof the propeller and including a pair of relatively-rotatable membersfor varying one of said limits.

10. In a propeller having a plurality of blades, means actuated by thethrust of the blades for automatically varying the pitch thereof, meansfor predetermining the extent of operation of said, pitch-varying meanswithin predetermined limits, 5 and means manually operable duringrotation of the propeller for varying one of said limits, said -lastnamed means including relatively-movable threaded members and gear meansfor rotating one of said members. 11. A variable pitch propellercomprising a rotatable shaft, a hub drivably connected to and movableaxially of said shaft, al plurality o f blades rotatably carried by saidhub, means responsive to axial movement of said hub for varyl5 ing thepitch of the blades, a stop mechanism positioned exteriorly of the hub,means carried by the hub and movable therewith into engagement with saidstop mechanism during axial movement of the hub with respect to theshaft in order to limit such movement, and means manually operableduring rotation of the propeller for variably adjusting the position ofsaid stop mechanism independently of said movement of the hub.

12. A Variable pitch propeller comprising a rotatable shaft, a hubdrivably connected to and movable axially of said shaft, a plurality ofblades rotatably-carried by said hub, means responsive to axial movementof said hub for varying the pitch of the blades, a stop mechanismpositioned exteriorly of the hub and concentrically arranged withrespect to the shaft,.means carried by the hub and movable therewithinto engagement with said stop mechanism during axial movement of thehub with respect to the shaft in order to limit such 'movement of thehub in the direction to effect a reduction in the pitch, and meansmanually operable during rotation of the propeller for variablyadjusting 4 the position of said stip mechanism, said manually-operablemeans including a pair of cooperating relatively-movable members.

13. In a variable pitch propeller of the type having a hub movable alonga propeller shaft in accordance with a variable condition of operationof the propeller, the combination with said propeller, of means operableto vary the pitch of the propeller during such movement of the hub,means to predetermine the extent of such movement and hence the limit ofchange in pitch of the propeller, and means manually operable duringrotation of the propeller to vary the position of said second' namedmeans independently of said movement of the hub.

14. In a propeller having pitch-variable blades, means for limiting thereduction in pitch of the blades, and means including a screw and nutmechanism and operable during rotation of the propeller for varying theposition of said limiting means.-

15. In a mechanism for limiting the change in pitch of a p'ropeller ofthe type having a member movable during change in pitch, a stationarythreaded member, a nut cooperating with said threaded member, means torotate said nut during operation of the propeller to variably positionthe same with respect to the threaded member, and means cooperating withsaid nut and forming a stop engageable with said movable member duringchange in pitch.

16. In a variable vpitch propeller of the type having a hub movablealong a propeller shaft in accordance with a variable condition ofoperation of the propeller, the combination with said 10 threaded nutcooperating with said threaded sleeve, an abutment associated with saidnut and positioned to be engaged by said stop member during movement ofthe hub along the shaft to limit the change in pitch of the propeller,and means manually operable during rotation of the propeller forrotating said nut and abutment whereby said abutment will be variablypositioned with respect to said stop member.

CLINTON H. HAVILL.

